1. Field of the Invention
This invention relates to surfactant compositions which are effective in dispersing water-insoluble liquids in aqueous liquids or aqueous solutions of strongly ionizable salts.
2. Description of the Prior Art
The use of biocides, which term includes various toxicants separately classified as insecticides, fungicides, weed killers, insect repellants, nematocides, rodenticides, etc., is widewpread in the agricultural industry where it is conventional to apply the biocide as an aqueous dispersion or emulsion. The application of combinations of biocides and liquid fertilizers in a single stage results in savings of labor and provides efficient use of spray application equipment.
The use of liquid fertilizer compositions with various herbicides is discussed by Lindner in Chapter 4 of Pesticide Formulations, edited by W. Van Valkenburg, Marcel Dekker, Inc., New York, 1973. Lindner in U.S. Pat. No. 3,236,627 provides dispersants useful in preparing liquid fertilizer biocide emulsions which exhibit stability only over periods of several hours. The blend of surfactants disclosed by Lindner can be, for instance, a mixture of the adduct of one mole of nonylphenol and one mole of ethylene oxide with maleic anhydride to form the monomaleic acid ester of nonylphenol mono-ethylene glycol monoether which is further reacted with ammonium bisulfite to produce the sulfosuccinic acid ester thereof. The alkali metal or ammonium salt thereof is useful in combination with a second surfactant component which is an mono-ethylene glycol monoether which is further reacted with ammonium bisulfite to produce the sulfosuccinic acid ester thereof. The alkali metal or ammonium salt thereof is useful in combination with a second surfactant component which is an amine salt of an alkyl benzene sulfonic acid. In U.S. Pat. No. 3,317,305, there is provided a phosphate ester emulsifier as a means of providing stable emulsions of various biocides in liquid fertilizer compositions containing high concentrations of electrolytes and/or other nutrient materials such as urea.
In no one of the above prior art references is there disclosed the use of a single anionic stabilizer or combination thereof with a conventional anionic emulsifier to provide stable emulsifiers of various biocides in commonly-used liquid fertilizer solutions containing strongly ionizable salts, as well as other nutrients such as urea.